This invention relates to manually operable change speed transmissions for motor vehicles and more particularly to a novel lock-out mechanism for a four shift rail manual transmission.
In vehicles having manual change speed transmission, wherein gears are shiftable by axially reciprocable shift rails, there is a need to prevent the shiftable gears from being accidently moved out of their preselected positions. Examples of prior art plate-like dual lug interlocking devices may be found in U.S. Pat. Nos. 4,633,729 and 4,633,730 issued Jan. 6, 1987 and assigned to the same assignee as the instant invention. While the interlocking dual lug arrangements of these patents are suitable for three shift rail transmissions they are not applicable to four shift rail transmissions. Further, in the above patent the dual lugs must either be interlocked between the three rails or supported on a horizontally disposed shoulder or the like.
Still other examples of three shift rail locking arrangements are disclosed in the U.S. Pat. Nos. 3,104,558 issued Sept. 24, 1963 and 1,537,584 issued May 12, 1925.